This adapter is passive and has no effect on the voltage. The power supply that you connect to this adapter must "understand" the voltage. In Japan, 100V voltage is common. As far as I know, "our" power supply units can also handle the Japanese 100V voltage. In most cases, this is also stated on the power supply unit -> Input: 100-240Volt / 50-60Herz. In other words, this adapter will be able to charge your devices in Japan.

Yes, it fits. Provided your devices do not have a protective earth conductor (earth, PE).

According to research: This adapter is made for travelling to USA/Japan, not for operating devices in Thailand. This product is best suited for travelling abroad: Skross PRO - World Travel Adapter

Cuba has four types of plug: type A (two-pin), type B (three-pin), which are both used in the USA and Canada, and type C and type L, which are *not* used in the USA. The adapter you are looking at allows a two-pin Swiss plug to connect to a type A socket. Voltage and frequency in Switzerland are 220 V and 50 Hz. In Cuba, they are 110 V/220 V and 60 Hz. Most of the time, it's 110 V, the same as that used in the United States and Canada. But it seems that *some hotels* have 220 V. So if your appliance is designed to work in the 110 V to 220 V range and can adapt automatically, then all is well. If your appliance operates at 220 V (check the sticker, the information printed on it or the instructions), you can only use it with this simple adapter in a place that supplies 220 V, i.e. one of the hotels mentioned. If you wish to use a 220 V appliance anywhere else, you will need a transformer with 110 V input and 220 V output.

Yes